Northern Catalpa (Speciosa)

The Northern Catalpa (Speciosa) is generally described as a perennial tree. This is native to the U.S. (United States) has its most active growth period in the spring . The Northern Catalpa (Speciosa) has dark green foliage and inconspicuous white flowers, with a moderate amount of conspicuous brown fruits or seeds. The greatest bloom is usually observed in the early summer, with fruit and seed production starting in the fall and continuing until fall. Leaves are not retained year to year. The Northern Catalpa (Speciosa) has a long life span relative to most other plant species and a rapid growth rate. At maturity, the typical Northern Catalpa (Speciosa) will reach up to 60 feet high, with a maximum height at 20 years of 20 feet.

The Northern Catalpa (Speciosa) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, seed. It has a slow ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -38°F. has medium tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Horticultural: Northern catalpa (Catalpa speciosa (Warder) Warder ex Engelm.) is primarily used today as a large ornamental shade tree. It is widely planted in urban areas as a street and lawn tree. When flowering, it has abundant showy blossoms.

Conservation: Conservation uses include being planted in mined-land reclamation projects and shelterbelts.

European settlers planted it to produce fence posts. The wood is lightweight, and the heartwood is resistant to deterioration when placed in the ground for several years. Railroad companies grew plantations of it for use as track ties and fuelwood. It was also used for making packing materials. Carpenters commonly used it for interior trim in houses. Craftsmen used it to make furniture. It has also been used as telephone or powerline poles.

Ethnobotany: In some of the older medical journals (19th century) there were speculations that catalpa gave off poisonous emanations. However, there is no scientific evidence to prove those speculations.

Pioneer doctors used the seed pods and seeds to make a decoction for chronic bronchial affections, spasmodic asthma, labored breathing and heart problems. The juice from either the leaves or roots was used to treat swelling of an eye or cutaneous affections. Green leaves were crushed and placed on swollen lymph glands. The bark was dried then ground up to powder and taken, or brewed in a tea and taken for swollen lymph glands.

Modern pharmaceutical research has shown catalpa trees are diuretic.

It is sometimes planted to attract the green catalpa worms, which are prized fish bait. These caterpillars can be frozen and used as bait at a later time.

General Characteristics

General: It is a perennial deciduous tree which readily grows in USDA Hardiness Zones 4 to 8. It has moderate to fast growth, tending to grow rapidly when juvenile, but slows with maturity.

The height at 20 years is about 20 feet. The biggest northern catalpa recorded is in Indiana. It is 81 feet tall with a spread of 84 feet and a circumference of 285 inches at Diameter Breast High (dbh) at 4.5 feet above ground level. Catalpas prefer moist, deep, well drained soil, but adapts to dry or wet soils. The soil pH may range from 5.5 to 7.0. It prefers an open sunny space to partial shade. When it grows from seed the tree trunk rarely divides into two or more branches about the same size. If the tree is cut and grows back there is prolific spouting from the stump. The bole may be straight, but it is usually crooked. It is tall with an irregular, open-rounded to narrow-oval crown. This tree comes into leaf very late in the spring and it is one of the first to lose its leaves in the fall. Its longevity is about 60 years.

The tree bark ranges from scaly to ridged, to blocky plates. On a mature tree trunk the bark may be from ¾ to 1 inch thick, light grayish brown in color, and broken into longitudinal, scaly, flat ridges. On young tree seedlings the bark is thin and easily damaged by impact, or rodents.

Twigs in winter have a unique identifying characteristic. They have sunken leaf scars which resemble suction cups. Their whorled arrangement of 3 scars per node is another trait easily identified.

Leaves are simple, large ovate to ovate-oblong, from 8 to 12 inches long, are heart-shaped tropical looking without any lobes and are yellowish green in color. The leaf margins are entire, pointed at the tips and rounded to cordate at the bases. The top of the leaf is darker green than the underside which is also pubescent. Leaves are generally opposite on large branches and often whorled in 3 on young stems. Leaves may scorch and drop during droughts. They turn an undistinguished yellow in the fall before dropping. The leaves do not emit an unpleasant aroma when bruised as is the case with the southern catalpa (Catalpa bignonioides Walt.), which are also more abruptly pointed.

The flowers of catalpa are perfect. Flowering takes place in late spring to early summer. They occur as large clusters of showy, white, bell-shaped corollas of 5 lobes with ruffled edges and yellow, orange or purple interior spotting or streaking. Individual flowers are showy, tubular up to ½ inch broad. They are branched in about 10 inch clusters at the stem tips. The northern catalpa flowers about 2 to 3 weeks earlier than the southern catalpa, which also has more spotted flowers. Flowers are good for honey production.

Seedpods are slender and green in the summer growing from 10 to 24 inches long, looking similar to an exaggerated green bean. They mature in the fall, turn dark brown, split open lengthwise to let seeds fall in the spring. The whole pod is often blown off the tree. The shape and color of the mature seedpod gives rise to the common name of cigar tree.

The southern catalpa seeds are drawn out more to a point while the northern catalpas seeds are more blunt at the end. Seeds are about 1 inch long and 1/3 inch wide. They have a light brown coat and wings rounded at the ends terminating in a fringe of short hairs. There are approximately 20,480 seeds per pound. Seeds which are collected after overwintering in the mature seedpod have a higher germination rate than those collected in the fall and stored.

The wood is of moderately light density (specific gravity 0.42 ovendry), with pale gray sapwood and grayish brown heartwood. It has a faint, aromatic, noncharacteristic odor and no characteristic taste. It is ring porus, coarse-grained, soft, not strong, but very durable in contact with the soil.

Required Growing Conditions

For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Habitat: Prior to European settlement it was native to a small area of the central Mississippi Valley basin, western Tennessee, north east Arkansas, the lowlands of south east Mississippi and southern Illinois and Indiana. It is now readily found from Kansas south to Texas and eastward to Louisiana.

Adaptation It has been extensively propagated for over 200 years. It can now be found in most eastern states, and planted to some extent in Europe and New Zealand.

Cultivation and Care

When placed as an ornamental in a yard setting care must be taken to ensure it is not too close to a building, fence, property line or septic system. Ample space should be provided to let it reach a mature height.

Status

Weediness This plant may become weedy or invasive in some regions or habitats and may displace desirable vegetation if not properly managed.

General Upkeep and Control

The biggest management problem with a catalpa tree used as an ornamental is litter. It will drop a heavy load of flowers in the spring then a plentiful supply of leaves in the fall and finally a lot of large seedpods in the winter.

Pests and Potential Problems Larva of the catalpa sphinx caterpillar (Ceratomia catalpae) eats leaves. Almost complete defoliation may occur in some years. When the catalpa sphinx eats the leaves, significantly more nectar than normal seeps out of the damaged leaf. This increased nectar attracts various species of ants, ladybird beetles and a parasitoid. These predaceous insects attack and/or remove the eggs and young larvae of the catalpa sphinx. The secretion of extrafloral nectar and its subsequent harvesting by insects is mutually beneficial to both the catalpa tree and the predaceous insects. Rabbits are especially damaging in their girdling of young stems.

Immature seeds in the pods are often destroyed by a small yellow grub, the larva of a gnat.

Catalpa midge (Cecidomyia catalpae Comstock) causes leaf spots, injures terminal buds and branch tips, as well as seeds in the pods.

Brown leaf spots on leaves are often created by the fungi Macrosporium catalpae. This is rarely a serious problem so no chemical treatment is recommended. Catalpa is also susceptible to the decay fungus Polystictus versicolor. It can severely damage catalpa trees after about 20 years of age in the western part of its planted range.

Powdery mildew causes a white powdery coating on the leaves. When severe the leaves turn yellow and drop.

Verticillum wilt will make the branches die, and can eventually kill trees. A hard to find symptom of verticillum wilt is discoloration of the sapwood.

Environmental Concerns It is an invasive, weedy tree which escapes cultivation easily. The flowers, long seedpods and seeds fall down from spring through winter, and create a mess on the ground anywhere near the tree. Its brittle wood makes its branches subject to wind and ice damage.

Seeds and Plant Production Catalpas can readily be grown from seed. Research shows seeds collected after overwintering in the seedpods had better germination than those collected in the fall and stored inside. Root cuttings may also be used to propagate trees.

Plant Basics
Category
Growth Rate Rapid
General Type Tree
Growth Period Spring
Growth Duration Perennial
Lifespan Long
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Early Summer
Displays Fall Colors Yes
Shape/Growth Form Single Stem
Drought Tolerance Medium
Shade Tolerance Intolerant
Height When Mature 60
Vegetative Spread Slow
Flower Color White
Flower Conspicuousness Yes
Fruit/Seed Abundance Medium
Fruit/Seed Seasonality Fall Fall
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Bare Root, Container, Seed
Moisture Requirements Low
Cold Stratification Required No
Minimum Temperature -38
Soil Depth for Roots 20
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Resprout Ability Yes
Responds to Coppicing No
Growth Requirements
pH Range 5.5–7 pH
Precipitation Range 20–20 inches/yr
Planting Density 100–1200 indiv./acre
Soil Textures Coarse, Medium
Soil Depth for Roots 20
Minimum Frost-Free Days 90 day(s)
Salinity Tolerance Low
CaCO3 Tolerance Low
Sustainability & Use
Leaf Retention No
Palatability Low
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database, plants.usda.gov.
National Plant Data Center, Baton Rouge, LA 70874-4490 USA